Large liquid analyzers such as the blood analyzers described in U.S. Pat. No. 4,512,952 have been very successful in testing body liquids using dried test elements sometimes identified as "slides". One of the reasons for this has been the high throughput that such analyzers provide, and the high degree of accuracy and precision that is possible. On the other hand, there remain some minor disadvantages. These stem from the fact that there have been used in such analyzers, three different kinds of slide test elements--colorimetric end-point types, hereinafter "CM" types; rate types; and potentiometric types, hereinafter "PM" types. Each type has needed its own incubation and reading station. Examples are shown in, e.g., the aforesaid U.S. Patent. Due to the need for three incubators and their separate read stations, such analyzers have taken up considerable space. Furthermore, triplicating the incubators and read stations has added considerably to the cost.
A further disadvantage of some analyzers has been the amount of space required. Every time an additional function is added, the apparatus for that function has been simply "added on", producing a machine wherein no attempt is made to use space most efficiently.
Japanese Kokai 61/209341 describes a rotating incubator, FIG. 5, which is said to be useful, p. 14, for CM type test elements or rate-type. However, PM types are not mentioned, nor are the test elements supplied from sources that provide for maximum utilization of space in the analyzer.
Therefore, prior to this invention, there has been the need for a blood analyzer having high throughput, accuracy and precision as in the above-noted prior analyzer, but using fewer stations in a more efficient manner to require less room and less cost.